Moisture-responsive systems which protect the interior of a motor vehicle from water damage by closing all open external openings, such as windows, sun roofs, convertible tops, etc., in response to the detection of rain are known. Such systems generally include a moisture-sensitive probe arranged to detect moisture outside of the vehicle and which produces a signal responsive to detecting an excessive moisture condition. The signal produced by the probe is impressed upon a switch which activates a circuit for producing signals which are received by motorized mechanisms for closing window structures and the like.
One such system typical of the prior art is disclosed in U.S. Pat. No. 2,994,525. In that system, a signal from a moisture sensor actuates a series of relays which cause a motor to rotate a drive shaft which carries a plurality of cams. The cams of the rotating shaft sequentially actuate individual window motors. The motors have limited torque output and as a result, a motor will stall when an obstruction in its corresponding window is encountered.
Another such system is disclosed in U.S. Pat. No. 2,823,346. That system closes all openings in response to the detection of rain, but reopens such openings when rain is no longer detected unless the doors of the motor vehicle have been previously locked. The reopening of the windows avoids the build up of heat within the closed vehicle while the detection of locked doors ensures security by maintaining the windows in a closed position.
None of the systems of the prior art accommodates the possibility that an obstruction which prevents the closure of an opening may only be temporary. For example, the obstruction may simply be a person's arm resting on top of a window preventing the window from rising to its closed position. When an obstruction is encountered by the systems of the prior art, such systems simply leave the window, sunroof, etc., in the stalled position. Thus, if the obstruction is only temporary, the opening would still be left open permitting rain water to enter the interior of the vehicle and possibly cause water damage.